1. Field of the Invention
This invention is related to amorphous N-[N-(3,3-dimethylbutyl)-L-.alpha.-aspartyl]-L-phenylalanine 1-methyl ester (neotame). The invention is also directed to processes of preparing amorphous neotame, such as by melt-processing. Amorphous neotame is advantageous compared to other forms of neotame because of improved solubility and dissolution.
2. Related Background Art
Neotame is a known sweetener that has a sweetening potency that is about 40 times that of aspartame and about 8,000 times that of sucrose. N-[N-(3,3-dimethylbutyl)-L-.alpha.-aspartyl]-L-phenylalanine 1-methyl ester may be prepared from aspartame as described in U.S. Pat. Nos. 5,480,668, 5,510,508 and 5,728,862, all of which are incorporated by reference herein.
As described in those patents, neotame is crystallized from a methanol/water solution to provide neotame monohydrate, i.e., one molecule of water and one molecule of neotame. The crystal structure of neotame monohydrate is known. See e.g., "Neotame, an alkylated dipeptide and high intensity sweetener", Acta Cryst. (1999) C55, 1365-1368.